1. Field of the Invention
The present invention relates to the handling of waste ink accumulated in an ink jet printer system, and more particularly, to an apparatus for decreasing ink misting during a printhead nozzle purge operation.
2. Description of the Related Art
Ink jet printers require maintenance operations to keep the nozzles of the print cartridge operating properly. Such maintenance operations typically include the steps of wiping the nozzle area of the print cartridge, firing the nozzles at prescribed intervals to purge the nozzles (spitting), and capping the cartridge during idle periods to prevent the jetted ink which remains on the nozzle plate from drying and clogging one or more of the nozzles of the nozzle plate. Typically, the spitting operation occurs at a location in the maintenance station. Over a period of time, the solids in the waste ink accumulate in the maintenance station, and the resulting waste ink build-up can affect the operation of the maintenance assembly.
Ink jet printers have been plagued with the problem of ink mist from maintenance operations drifting around and landing on the print media which is being printed. The mist is generated when the printer stops periodically to clean and clear the printing nozzles by spitting ink. When the printer resumes printing on the print media, airborne mist from the maintenance operation is drawn by the carrier movement and drifts onto the paper. This results in a noticeable image defect on the paper, and tends to also contaminate other printer mechanisms.
One previous attempt to control and collect the mist ink is to perform the spitting operation on-page. Other printers have used fans and absorbent pads in attempts to collect and contain the mist ink. However, with the more prevalent use of higher non-volatile constituents in ink formulations, residual or waste ink build-up interferes with the operation of printing by contaminating the printheads. Furthermore, passive collection systems, such as pads and venturies, have limited effectiveness and limited capability to store non-volatile waste ink. Active systems, such as fans, can be effective, but are complex and expensive to implement.
Other attempts have included providing a rotating annular wheel for receiving waste ink discharged by an ink jet printhead which is driven by a rotary capping assembly which is rotated by a motor and gear or belt. Such a configuration, however, is not readily adaptable for use with sled-type maintenance assemblies, since such sled-type maintenance assemblies do not include a source of rotary motion. In addition, a curvature of the annular wheel is not uniformly spaced from the generally parallel columns of nozzles of the printhead, thereby limiting its effectiveness for waste ink mist recovery.
Accordingly, a need exists for a printing system which includes a simple and effective drive mechanism to provide rotary power to a sled-type maintenance assembly and provides improved waste ink mist recovery.